Pickproof locks



Nov. 24, 1970 F. A. MURPHY 3,541,322

PICKPROOF LOCK Filed June 28, 1968 3 Sheets-Sheet 1 k 1 (PP/on Apr FIG. I

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PICKPROOF LOCK Filed June 28, 1968 3 Sheets-Sheet 2 INVENTOR.

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PICKPROOF LOCK Filed June 28, 1968 3 Sheets-Sheet 5 INVENTOR. FPED MUQPl/Y BY W A Trap/vs):

United States Patent 3,541,822 PICKPROOF LOCKS Fred A. Murphy, 1512 Commonwealth Ave., Bronx, NY. 10460 Filed June 28, 1968, Ser. No. 741,168 Int. Cl. Eb 15/14 US. Cl. 70-421 4 Claims ABSTRACT OF THE DISCLOSURE The present invention provides a preventative against unauthorized opening of a cylinder lock such as by picking in a manner which voids the cylinder plug of the tumbler. There is provided auxiliary pins which intersect the tumbler receptacle chambers on the cylinder plug at a point along its rotational path to relock the cylinder plug. There is further provided means to set the auxiliary pins against displacement and means to provide a momentary stop in the cylinder plug rotation to afford the auxiliary pins an opportunity to engage.

The present invention relates to pickproof locks.

Cylinder locks are in widespread use today and in most instances they represent the major protective device for the safety of persons and property against unauthorized interference. These locks generally are comprised of a housing and an inner cylinder plug. The inner cylinder plug has a plurality of openings along its top surface which align with the same amount of openings in the housing. Spring loaded pins or tumblers in the housing depend into the cylinder plug openings when a key is not in use, preventing it from being used unless a proper key is inserted. The tumblers line up at the shear line so that the cylinder plug may be revolved to lock and unlock the device. When a proper key is used, the lower or bottom tumbler sections ride within the cylinder plug during revolution with the spring biased upper tumbler sections maintained within their respective housing chambers by the cylinder plug body.

In the past, when an unauthorized person desired to pick such a lock, a picking device was placed into the cylinder plug through the keyway so as to raise the tumblers to their arranged alignment and thus allowing the cylinder plug to be revolved.

Since the tumblers are generally disposed in a substantially parallel alignment, with the proper tools, the cylinder plug can be made to revolve without use of a proper key.

Although various modifications have been made in the manufacture-of locks of this nature, such as by varying the type of tumbler employed or by disposing the tumblers in a non-aligned manner, such locks still can be actuated so as to free the cylinder plug for revolution by disposing the tumblers with other means than the proper key or keys.

According to the present invention, at least one and preferably a plurality of auxiliary pins and chambers are provided in the housing. The auxiliary pins and chambers are disposed within the housing so as to be in an intersecting plane with the cylinder plug chambers and are thus adapted to engage within the cylinder plug openings in the event of an attempted revolution of such cylinder plug in the absence of a proper key.

If a lock were attempted to be picked by the raising of the tumblers to free the cylinder plug, the cylinder plug will relock after picking the first chamber tumblers in the secondary or auxiliary chambers.

While this relocking would generally discourage any further attempts at unwarranted opening, such as by atice.

tempting to disengage the auxiliary pin, in its preferred embodiments, the lock of the present invention is provided with means to permanently set the auxiliary pin against displacement.

Means have also been provided in the lock of the present invention to prevent the bypass of the auxiliary pins by, for example, the rapid spinning of the cylinder plug after picking of the first set of tumblers. Additionally, to prevent the undesired actuation of the safety mechanisms, the removal of a proper key has been inhibited until a position of desired alignment has been obtained.

Although such a novel feature or features believed to be characteristic of the invention are pointed out in the claims, the invention and the manner in which it may be carried out may be further understood by reference to the description following and the accompanying drawrngs.

FIG. 1 is a perspective view partly in phantom of a lock of the prior art.

FIG. 2 is a side elevation of a lock of the present invention.

FIG. 3 is a sectional view in perspective taken along lines 33 of FIG. 2 with the tumblers and pins not shown.

FIG. 4 is a perspective view of a cylinder plug of the present invention.

FIG. 5 is a cross sectional view of the lock of the present invention in locked position.

FIG. 6 is a cross sectional view of the lock of the present invention with the tumbler positioned upward within the housing chamber.

FIG. 7 is a cross sectional view of the auxiliary pin of the present invention in actuated position within the cylinder plug.

FIG. 8 is a side elevation of an auxiliary pin of the present invention.

FIG. 9 is a sectional view taken along lines 99 of FIG. 2.

FIG. 10 is a sectional view in prospective of an alternate embodiment of the present invention.

Referring now to the figures in greater detail, like reference numbers denote like parts in the various figures.

As shown in FIGS. 1-4, the lock 1 of the present inven tion includes the basic configuration of prior cylinder locks, that is, there is provided a housing 2 with a longitudinal bore therein and a revolving cylinder plug 3 therein. The housing 2 is provided with a plurality of tumbler chambers 4 and the cylinder plug 3 is provided with a plurality of tumbler receptacles 5. The tumbler chambers 4 open along the bore and align in registration to the tumbler receptacles 5.

As shown in FIGS. 1 and 5 each tumbler chamber 4 retains a spring 6 biased tumbler arrangement. In locked position tumblers, preferably of the split type having an upper tumbler section 7 and a lower tumbler section 8, are disposed within both the tumbler chamber 4 and the tumbler receptacles 5 so as to maintain the cylinder plug 3 against rotation.

As shown in FIG. 1, upon the insertion of a proper key 10 into the keyway 9 on the cylinder plug 3, the tumblers will be raised so as to dispose the upper tumbler section 7 fully within the tumbler chamber 4 and align the top of the lower tumbler section 8 along the shear line or periphery of the cylinder plug 3. In such position the cylinder plug 3 is free to rotate, the rotating cylinder plug 3 carrying the lower tumbler sections 8.

The lock 1 of the present invention, such as shown in FIG. 3, provides at least one, but preferably a plurality of supplemental chambers 11 disposed so as to exit along the bore in the housing 2, the chambers 11 exiting along the periphery of the housing bore so as to be aligned with the tumbler receptacles of the cylinder plug 3 at a point along the rotational path of the cylinder 3. It is desirable that the supplemental chambers 11 be positioned at a point so that the intersection with the cylinder plug 3 tumbler receptacles 5 be effected before the bolt (not shown) for the locking mechanism is actuated to release the lock.

Each supplemental chamber 11 is provided with an auxiliary pin 12. The auxiliary pin 12 is biased outward of the supplemental chamber by a spring 13, the auxiliary pin 12 maintained within the supplemental chamber 12 between the bias of the spring 13 and the periphery of the cylinder plug 3.

When the lock 1 is properly actuated by a key, the lower tumbler sections 8 within the tumbler receptacles 5 on the cylinder plug 3 are so aligned as to present an unbroken peripheral surface on the cylinder plug 3 thus maintaining the auxiliary pins 12 within their chambers 11.

In picking a lock, a picker attempts to raise one of the tumblers to the shear line then maintain such picked tumbler in position and pick the remaining tumblers. After picking each tumbler, the position of a picked tumbler, being shown in FIG. 7, the cylinder plug 3 is revolved. In the event, as sequentially shown in FIGS. 6 and 7, the cylinder plug 3 is revolved without a key the lower tumbler sections 8 drop by gravity into the tumbler receptacles and, upon juxtaposition during revolution of the tumbler receptacles 5 and the supplemental chambers 11, the auxiliary pins 12 will engage within the tumbler receptacles 5. Without the arrangement of the present invention, such dropping would have no adverse effect since the cylinder plug is free.

It is preferable that each auxiliary pin 12 be of a height sufficient to rest on the lower tumbler sections 8 within the tumbler receptacle 5 and extend to the supplemental chamber 11, thus preventing further rotation of the cylinder plug 3.

The auxiliary pin 13 as most clearly shown in FIG. 8 is preferably a mushroom-like cylindrical pin having its lower section 14 diameter equal to that of the lower tumbler section 8, and having an upper section 15 of like diameter. A portion 16 along the length of the auxiliary pin 12 is of a lesser diameter than upper and lower sections 14, 15.

So as to insure that the auxiliary pin 12 cannot be picked in a manner similar to that described with respect to the tumblers 7, 8, the housing 2, such as shown in FIGS. 3 and 5-7 is provided with a plurality of stop pin chambers 17 preferably, one stop pin chamber 17 for each supplemental chamber 11.

Each stop pin chamber 17 is disposed so as to intersect a supplemental chamber 11 and interconnect therewith, preferably at a right angle. A spring 18 loaded stop pin 19 in each stop pin chamber 17 is biased towards the supplemental chamber 11 and maintained between the periphery along the lower section 16 of the auxiliary pin 12 and the bias of the spring 18.

The stop pin 19 has a diameter slightly less than the distance between the upper section 15 and the lower section 16 of the auxiliary pin 12. When the auxiliary pin 12, such as shown in FIG. 7, is actuated to lock the cylinder plug 3 against rotation, the lesser diameter section 16 of the auxiliary pin 12 is juxtaposed to the intersection of the supplemental chamber 11 and the stop pin chamber 17 and the stop pin 19 nests therein, locking the auxiliary pin 12 in position. Due to the registry of the auxiliary pins 12, their locking of the cylinder plug 3 is substantially simultaneous.

As shown in FIGS. 4 and 9, a notch 20 may be provided on the periphery of the cylinder plug 3 along a plane parallel to the tumbler receptacles 5. A chamber 21 in parallel alignment to the supplemental chambers 11 is provided in the housing 2. The chamber 21 exits at a point along the bore in the housing 2 so as to align the chamber 21 to intersect with the notch 20 as the cylinder plug 3 is rotated. A spring 22 loaded ball 23 is biased outward of the chamber 21. As the cylinder plug 3 is rotated, the ball 23 engages within the notch 20 to provide a momentary stop to the cylinder plug 3 rotation. If a proper key is within the cylinder plug 3 the revolution of the cylinder plug 3 may be continued. However, if the tumbler receptacles 5 have been picked, during such momentary stop, the auxiliary pins 12 will engage within the tumbler receptacles 5 and the safety device of the present invention actuates.

So as to prevent an undesired actuation of the auxiliary pins 12 such as by the removal of a proper key at a point along the rotation of the cylinder plug 3 when the numbler receptacles 5 and the supplemental cham bers 11 are aligned, it is preferable that the number of auxiliary pins 12 and supplemental chambers 11 be less than the number of tumbler receptacles 5.

During the normal removal of a key the lower tumbler sections 8 ride upward and downward along undulating key surfaces. The lower tumbler sections 8 are free to move upward since they are aligned beneath their respective tumbler chambers 4. So as to prevent a like result when the tumbler receptacles 5 are in a position of alignment with the supplemental chambers 11, the number of supplemental chambers 11 is made less than the number of tumbler receptacles 5. Upon an attempt to remove a key, one or preferably two of the lower tumbler sections 8 are blocked from riding upward, but are rather locked between the housing 2 and the key thus making the key at such position irremoveable.

As shown in FIG. 10 in the event the cylinder plug 3 is of the type which may be revolved in either direction, the housing 2 may be provided with an additional set of supplemental chambers 11, auxiliary pins 12, stop pin chambers 17 and stop pins 19 and preferably the momentary stop ball 23 configuration.

Such arrangement is additionally desirable on a lock where the cylinder plug 3 revolves 360, thus providing a double safety arrangement within a single lock.

Thus, in operation a lock is provided which will positively immobilize a cylinder lock in the event of an improper attempt at actuation.

The terms and expressions which are employed are used as terms of description; it is recognized, though that various modifications are possible.

Having thus described certain forms of the invention in some detail, what is claimed is:

1. In a cylinder lock having a housing and a rotationally mounted cylinder plug within said housing, said housing including a plurality of biased sectioned tumblers, said cylinder plug having a plurality of openings along its surface adapted to receive a portion of said tumblers therein to lock said cylinder plug against rotation and key means adapted to align the section line of said tumblers along the periphery of said cylinder plug to release said cylinder plug for rotation, the improvement comprising a spring biased auxiliary pin for each tumbler mounted in said housing and biased towards said cylinder plug, said housing adapted to mount at least as many auxiliary pins as there are openings in said cylinder plug including tumblers, said auxiliary pins adapted to intersect said cylinder plug openings with a portion thereof adapted to seat therein upon rotation of said cylinder plug absent a key, said auxiliary pins locking said cylinder plug against rotation, said housing further including a spring biased stop pin mounted therein for. each auxiliary pin, said stop pin substantially radially aligned and inward of said housing, said stop pin biased toward the periphery of an auxiliary pin, said stop pin adapted to intersect with said auxiliary pin and lock said auxiliary pin against displacement upon the seating of a portion of said auxiliary pin within said cylinder plug opening, each said auxiliary pin being mushroom shaped having a lower portion having a diameter substantially equal to the diameter of said tumbler, and upper portion having a diameter substantially equal to said lower portion diameter with a lesser diameter portion between said upper and lower portion, said stop pin mounted in said housing biased toward said auxiliary pin and juxtaposed to said lower portion of said auxiliary pin, said stop pin having a diameter slightly less than the height of said lesser diameter portion, wherein a portion of said stop pin is adapted to nest within said lesser diameter portion upon the seating of said auxiliary pin within said cylinder plug opening.

2. The invention as claimed in claim 1 wherein said housing further includes biased means intersecting the periphery of said cylinder plug and said cylinder plug includes a notch along its periphery in registration to at least one of said cylinder plug openings, said biased means adapted to engage Within said notch at a point along the rotational path of said cylinder plug to momentarily stop the rotation of said cylinder plug.

References Cited UNITED STATES PATENTS 1,494,765 5/1924 Barrett 70-363 1,707,922 4/1929 Pepper 70-421 2,137,504 11/1938 OConnell 70364 3,195,330 7/1965 Bauer 70-421 3,260,082 7/1966 Bodek et a1 7O421 RICHARD E. MOORE, Primary Examiner R. L. WOLFE, Assistant Examiner US. Cl. X.'R. 70378, 386 

